One way of characterizing the cleaning performance of a vacuum cleaner is by reference to its so-called “pick-up” performance: the ability of the vacuum cleaner to pick up dirt and debris from a floor surface.
A desirable pick-up performance often includes the ability to pick up both fine dirt as well as so-called “large debris” such as, for example, certain pet snacks, breakfast cereals, grains of rice etc.
The design of the suction nozzle on a vacuum cleaner is one of the factors which determines the ability of a vacuum cleaner to pick up large debris.